Partition member and assembled battery

Abstract

A partition member includes an encapsulated body capable of retaining a liquid, and an outer package body for accommodating the encapsulated body and the liquid. The area S1 of the encapsulated body when the outer package body and the encapsulated body are seen in a planar view from the thickness direction and the area S2 of a gap between the outer package body and the encapsulated body satisfy the relationship represented by formula 1 below, and the volume V1 of the liquid and the volume V2 of the encapsulated body satisfy the relationship represented by formula 2 below.S1/(S1+S2)≤0.99 and  Formula 10.02≤V1/V2≤1.90  Formula 2

What is claimed is: 
     
       1. A partition member which has a thickness direction and a planar direction orthogonal to the thickness direction and which constitutes a partition between single batteries that constitute an assembled battery in the thickness direction or between a single battery that constitutes an assembled battery and a member other than the single battery, the partition member comprising:
 an encapsulated body capable of retaining a liquid; and 
 an outer package body for accommodating the encapsulated body and the liquid, wherein 
 the area S 1  of the encapsulated body when the outer package body and the encapsulated body are seen in a planar view from the thickness direction and the area S 2  of a gap between the outer package body and the encapsulated body satisfy the relationship represented by formula 1 below, 
 wherein the volume V 1  of the liquid and the volume V 2  of the encapsulated body satisfy the relationship represented by formula 2 below,
     S 1/( S 1+ S 2)≤0.99  Formula 1:
 
   0.02≤ V 1/ V 2≤1.90  Formula 2:,
 
 
 wherein the liquid retained in the encapsulated body moves to the gap between the outer package body and the encapsulated body as a result of deformation of the outer package body and the encapsulated body when the external pressure increases, and 
 wherein the gap is located between each side surface of the encapsulated body and the outer package body. 
 
     
     
       2. The partition member according to  claim 1 , wherein S 1  and S 2  above satisfy the relationship represented by formula 3 below
   0.10≤ S 1/( S 1+ S 2)≤0.99  Formula 3:
 
 
     
     
       3. The partition member according to  claim 1 , wherein the liquid that has moved to the gap between the outer package body and the encapsulated body moves to the inner part of the encapsulated body as a result of deformation of the outer package body and the encapsulated body when the external pressure decreases. 
     
     
       4. The partition member according to  claim 1 , wherein the encapsulated body is fixed in an internal space in the outer package body. 
     
     
       5. The partition member according to  claim 1 , wherein the air pressure in the internal space in the outer package body is lower than the air pressure outside the outer package body. 
     
     
       6. The partition member according to  claim 1 , wherein the encapsulated body is formed of a material that includes a porous body. 
     
     
       7. The partition member according to  claim 6 , wherein the porous body contains a fibrous substance and/or particles. 
     
     
       8. The partition member according to  claim 1 , wherein the outer package body is a laminated body of a metal foil and a resin. 
     
     
       9. The partition member according to  claim 8 , wherein the metal foil is at least one type selected from an aluminum foil, a copper foil, a tin foil, a nickel foil, a stainless steel foil, a lead foil, a tin-lead alloy foil, a bronze foil, a silver foil, an iridium foil and phosphor bronze. 
     
     
       10. The partition member according to  claim 8 , wherein the resin is a thermoplastic resin. 
     
     
       11. An assembled battery that is provided with the partition member according to  claim 1 . 
     
     
       12. The partition member according to  claim 1 , wherein when positioned between single batteries, the partition member is sized so as to not protrude above adjacent batteries in a height direction. 
     
     
       13. The partition member according to  claim 1 , wherein the gap of the partition member is located between the single batteries.